The cause of obesity is far from simple as imagined, and the mechanism of surprising results after weight loss surgery is also complex, just like obesity is not only the result of eating more, surgery changes not only the reduction of food intake, but also the endocrine environment in the body, including gastrointestinal hormones, energy balance, intestinal flora have been beneficial changes, which is also the effect of surgery is better than simple diet control. This is the fundamental reason why surgery is more effective than diet alone. Let us first understand the reasons for obesity. 1, genetics and prenatal factors early life in health is particularly important, because this will affect the future health of the body. In fact, the fetus in the womb when it can determine a lot of fetus later many health problems. Pregnant women’s diet and lifestyle choices are indeed important and can affect the future behavior and physical development of the baby. Some studies have shown that pregnant women who are overweight during pregnancy are more likely to deliver babies who are the same weight as a normal 3-year-old. It is also important to note that children of obese parents or grandparents are more likely to be obese than children of normal weight parents or grandparents. In addition, genes inherited from parents may determine the body’s susceptibility to weight gain. Although genetics and early life factors are not solely responsible for the development of obesity, they do predispose the body to weight gain. About 40% of overweight children continue to gain weight during adolescence, and 75?80% of obese adolescents will grow up to be obese adults. Summary: genetics, mother’s weight and family history can increase the chances of childhood and adult obesity. 2, the way of birth, infant and childhood habits Although the cause is not clear, but the risk of obesity is higher in children born by cesarean section. For formula-fed children as well, compared with breast-fed children, these children have a higher risk of obesity. This may be related to the different intestinal flora that develop in children fed in these two ways, which may affect the body’s fat storage. It is important to note that these factors are not usually chosen by the mother or the infant, but they appear to increase the risk of childhood obesity. In addition, the formation of healthy eating and exercise habits during childhood may be the most valuable preventive measure for obesity and lifestyle-related diseases. If children develop the habit of consuming healthy foods rather than junk food, this can help them maintain a normal weight throughout their lives. In conclusion: certain childhood factors may influence the risk of developing organic obesity. These factors include the way of birth, breastfeeding and childhood diet and exercise habits. 3, drugs or medical conditions Many health conditions and diseases require drug treatment. But unfortunately, weight gain is a common side effect of many drug treatments. These medications include diabetes medications, antidepressants and antipsychotics. These medications may increase the body’s appetite, decrease its metabolism, and even alter the body’s ability to burn fat – making it store fat instead of burning it. In addition, many common health conditions can lead to weight gain. A classic example of this is hypothyroidism. In summary: Weight gain is a common side effect of many medications. These include diabetes medications, antidepressants and antipsychotics. 4. Powerful hunger hormones Hunger and uncontrollable appetite are not only caused by the body’s greed or lack of willpower. Hunger is controlled by very powerful hormones and brain chemicals involved is responsible for the brain reward system of the brain region. Many obese people have impaired function of this hormone, which alters their eating behavior, resulting in a powerful physiological drive to consume more food. There is a reward center in the brain that turns on when we eat, which then secretes dopamine and other chemicals that make the body feel good. This is why most people like to eat. This system also ensures that we consume enough food to get all the energy and nutrients we need. The brain releases more “feel-good” chemicals after consuming junk food than unprocessed food, which creates a more powerful “reward” in the brain. The brain may create a powerful craving for these junk foods in order to seek more rewards. This can lead to a vicious cycle, similar to an addiction. The bottom line: hunger is controlled by powerful hormones. These hormones usually exist in obese people with impaired function, which can lead to a powerful physiological drive to make the body consume more food to form more fat. 5, leptin resistance Leptin is a very important hormone that helps regulate appetite and metabolism. It is produced by fat cells and sends signals to the brain to stop eating. Leptin regulates the amount of calories consumed and consumed by the body, and regulates the amount of fat stored in the body. Adipocytes contain more fat and therefore produce more leptin. Leptin is present in large amounts in obese people. However, obese people often have a disease state called leptin resistance. Therefore, even though there is a large amount of leptin in the body, the brain does not recognize this. Without receiving signals from leptin, the brain incorrectly assumes that the body is starving, even when it has more than enough fat to store. This causes the brain to change its physiology and behavior to restore the body’s “missing” fat. It increases hunger and reduces caloric consumption to prevent the body from starving. Trying to use “willpower” to resist leptin-driven hunger signals is almost impossible. In summary: leptin resistance is common in obese people. The brain does not feel the production of leptin, it will be wrong to think that the body is in a state of hunger, which will lead to a strong physiological drive, making the body to consume more food. 6, poor nutrition education There are endless advertisements, health claims, nutrition claims and unhealthy food in our society. Although nutrition is important, people are generally not taught how to eat properly. Teaching children about the importance of healthy eating and proper nutrition can help them make better choices later in life. Nutrition education is important, especially since eating habits and lifestyles developed during childhood can be carried into adulthood. In summary: It is important to teach children the importance of proper nutrition, but there is a general lack of nutrition education in society. 7, addictive junk food Some things can make people completely addicted. Food addiction includes addiction to junk food in the same way that drug addiction and drug addiction do. In fact, as many as 20 percent of people are addicted to food, and that number rises to about 25 percent for overweight and obese people. When you’re addicted to something, you lose your freedom of choice and your brain chemistry makes the decision for you. In summary: junk food can be addictive, up to 25% of overweight or obese people are addicted to food. 8, the role of intestinal bacteria Many recent studies have shown that intestinal bacteria are very important to the health of the body. Interestingly, obese people and normal weight people gut bacteria are often different. Overweight or obese people’s intestinal bacteria can be more effective in obtaining energy from food, increasing the total calories in the diet. Although we do not yet fully understand the relationship between body weight and gut bacteria, there is evidence that gut bacteria play an important role in the development of obesity. In summary: Different gut bacteria exist in obese people than in people of normal weight. This may lead to obese people store more fat. 9, the environment Some areas are difficult to buy healthy food. These areas are often called food deserts, usually urban residential areas or rural towns can not buy healthy and affordable food. This is mainly due to the lack of grocery stores, farmers’ markets, and healthy food suppliers in those areas. People who live in these areas are at a lower economic level and do not have access to a car to travel far to buy food. The inability to purchase healthy and fresh food limits diets and increases the risk of problems such as obesity. Other environmental factors also increase the risk of obesity, including artificial light from electric lights, computers, phones and televisions. Even though these artificial lights can increase the risk of obesity, most studies still attribute the problem to lack of exercise. However, exposure to light at night and changes in the body’s circadian rhythm also contribute to the development of obesity. Animal studies have shown that artificial light can alter the circadian rhythm of the body, leading to a predisposition to obesity and metabolic syndrome in rodents. In summary: Some environmental factors that can make us more prone to obesity include food deserts and artificial light exposure.